Realated to pollution created out of a factory

There is a factory dealing with preparation n processing of coal-tar, situated in residential area on a non-registered plot of land. the gasses emitted out of it r so noxious n intense that it become difficult to breath almost for few seconds. Moreover, the factory works any time..day or mid-night.. doesn't matter. what legal help is there for residents. Also acquaint with lwas applicable as per the facts.